Abstract: A variable-color region (886) extending to an exposed surface (102) at a surface zone (892) having a boundary (1212 or 1214) responds to an object (104) impacting the zone sufficiently hard to meet threshold impact criteria at an object-contact area (896) by changing color at a corresponding print area (898) or by providing an impact signal that causes color change at the print area if supplemental impact criteria are also met. In either case, a smoothened image of the print area is produced by determining a portion of the boundary where the print area is nearest the boundary, approximating at least that boundary portion as a smooth boundary vicinity curve, approximating the print area's perimeter, or a portion thereof nearest the boundary, as a smooth perimeter vicinity curve, and comparing the vicinity curves to determine if they meet or overlap.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a closely matching print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria. Object-tracking apparatus (808) tracks movement of the object over the surface and provides an image-causing tracking impact signal when the object impacts the zone according to the tracking. An image-generating system (802, 842, 1152, or 1182) responds to at least the impact signal by generating a print-area vicinity image consisting of an image of the print area and adjacent area of the surface.

Abstract: A variable-color region (106) extends to an exposed surface (102) at a zone (112) and normally appears along it as a principal color. The region responds to an object (104) impacting the zone sufficiently hard at an object-contact area (116) by providing an impact signal identifying a criteria-meeting area (1626) where threshold impact criteria are met. Responsive to the impact signal and possibly to supplemental impact criteria being met, a controller (1622) produces a representation of a print area (118) from a representation of the criteria-meeting area by smoothening its perimeter and provides an initiation signal designating a location in the zone for the print area such that it closely matches the object-contact area. An impact-dependent portion (138) of the region responds to the initiation signal and possibly to a tracking condition being met by temporarily appearing along the print area as changed color materially different from the principal color.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily emitting light suitable for forming color different from the principal color if the impact meets threshold impact criteria such that the impact-dependent portion temporarily appears along a print area (118) of the zone as changed color materially different from the principal color. The print area closely matches the object-contact area in size, shape, and location. Use of light emission to produce the temporary color change is advantageous because the changed color can be virtually any possible visible color.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive and color-change components (182 and (184). A segment (192) of the impact-sensitive component responds to an object (104) impacting the zone at an object-contact area (116) by providing an impact effect if the impact meets threshold impact criteria. A segment (194) of the color-change component responds to the effect by causing an impact-dependent portion (138) of the variable-color region to temporarily appear along a print area (118) of the zone as changed color materially different from the principal color. The print area closely matches the object-contact area. The object subsequently leaves the object-contact area. The impact-dependent portion first appears as the changed color no more than 0.2 s after the object leaves the object-contact area.

Abstract: A variable-color region (106) extends to an exposed surface (102) at a zone (112) and normally appears along it as a principal color. The region responds to an object (104) impacting the zone sufficiently hard at an object-contact area (116) by providing an impact signal identifying a criteria-meeting area (1626) where threshold impact criteria are met. Responsive to the impact signal and possibly to supplemental impact criteria being met, a controller (1622) produces a representation of a print area (118) from a representation of the criteria-meeting area by smoothening its perimeter and provides an initiation signal designating a location in the zone for the print area such that it closely matches the object-contact area. An impact-dependent portion (138) of the region responds to the initiation signal and possibly to a tracking condition being met by temporarily appearing along the print area as changed color materially different from the principal color.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive color-change structure (132) and protective structure (242) lying at least partly between the zone and the impact-sensitive color-change structure. A segment (142) of the impact-sensitive color-change structure responds to an object (104) impacting the zone at an object-contact area (116) by causing an impact-dependent portion (138) of the variable-color region to temporarily appear, typically via light emission, along a print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria. The print area closely matches the object-contact area in size, shape, and location.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and contains multiple variable-color cells (404), each extending to a part (406) of the zone. The cells normally appear along their parts of the zone as a principal color. Each cell that meets cellular threshold impact criteria in response to an object (104) impacting the zone at an object-contact area (116) temporarily becomes a criteria-meeting cell that temporarily appears along its part of the zone as changed color materially different from the principal color. A group of less than all the cells usually constitute criteria-meeting cells. The surface parts of the criteria-meeting cells form a print area (118) that closely matches the object-contact area in size, shape, and location. The color-change capability helps in making in/out calls in sports such as tennis.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive and color-change components (182 and 184). A segment (192) of the impact-sensitive component responds to an object (104) impacting the zone at an object-contact area (116) by providing an impact effect if the impact meets threshold impact criteria. A segment (194) of the color-change component responds to the effect by causing an impact-dependent portion (138) of the variable-color region to temporarily appear along a print area (118) of the zone as changed color materially different from the principal color. The print area closely matches the object-contact area in size, shape, and location. The color-change component employs an electrode assembly (202) having a core layer (222) sandwiched between two electrode structures (224 and 226) for controlling the color change.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive color-change structure (132) and duration-extension structure (242). A segment (142) of the impact-sensitive color-change structure responds to an object (104) impacting the zone at an object-contact area (116) by causing an impact-dependent portion (138) of the variable-color region to temporarily appear along a print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria. The print area closely matches the object-contact area in size, shape, and location. The duration-extension structure responds to the impact by causing the impact-sensitive color-change structure to deform along an internal deformation area (288).

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a closely matching print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria. Object-tracking apparatus (808) tracks movement of the object over the surface and provides an image-causing tracking impact signal when the object impacts the zone according to the tracking. An image-generating system (802, 842, 1152, or 1182) responds to at least the impact signal by generating a print-area vicinity image consisting of an image of the print area and adjacent area of the surface.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive and color-change components 182 and (184). A segment (192) of the impact-sensitive component responds to an object (104) impacting the zone at an object-contact area (116) by providing an impact effect if the impact meets threshold impact criteria. A segment (194) of the color-change component responds to the impact effect by causing an impact-dependent portion (138) of the variable-color region to temporarily appear along a print area (118) of the zone as changed color materially different from the principal color. The print area closely matches the object-contact area in size, shape, and location. The color-change capability helps, for instance, in making in/out calls in sports such as tennis.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria. The print area closely matches the object-contact area in size, shape, and location. An image-generating controller (806) responds to the impact by causing an image-generating structure (804) to generate an image of the print area and adjacent surface extending to at least a selected location of the exposed surface if the threshold impact criteria are met. The image assists in determining how close the impact occurred to the selected surface location.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria. The print area closely matches the object-contact area in size, shape, and location. The color-change time duration of the impact-dependent portion temporarily appearing as the changed color is in a duration range established prior to the impact. A controller (602) responds to both the impact and subsequent external instruction (608) by controlling the impact-dependent portion so as to adjust the color-change duration subsequent to the impact.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. The region responds to an object (104) impacting the zone at an object-contact area (116) by providing an impact signal if the impact meets threshold impact criteria. The impact signal identifies a threshold criteria-meeting area (1626 or 1626) where the criteria are met in the zone. Responsive to the impact signal, a controller (1622 or 1632) provides an initiation signal that designates a print area (118) in the zone such that the print area is larger than the criteria-meeting area and can closely match the object-contact area in size, shape, and location. An impact-dependent portion (138) of the region responds to the initiation signal by temporarily appearing along the print area as changed color materially different from the principal color.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An object-tracking control apparatus (808) tracks movement of an object (104) over the surface. As the object impacts the zone at an object-contact area (116), an impact-dependent portion (138) of the VC region temporarily appears along a print area (118) of the zone as changed color materially different from the principal color if the impact meets threshold impact criteria and if the tracking indicates that the object is highly likely to impact the object-contact area. The print area closely matches the object-contact area in size, shape, and location. Impacts of bodies not tracked by the control apparatus substantially do not cause color change so that color change occurs substantially only for suitable impacts of the tracked object.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a print area (118) of the zone as generic changed color materially different from the principal color. The print area closely matches the object-contact area in size, shape, and location. The threshold impact criteria consist of multiple sets of different threshold impact criteria respectively associated with multiple specific changed colors materially different from the principal color. If the impact meets the threshold impact criteria, the generic changed color is the specific changed color for the criteria set met by the impact.

Abstract: A variable-color region (106) of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a print area (118) of the zone as generic changed color materially different from the principal color. The print area closely matches the object-contact area in size, shape, and location. Sound-generating apparatus (602 or 702) selectively generates a specified audible sound in response to the object impacting the object-contact area so as to meet the threshold impact criteria. The specified sound is separate from any audible sound originating at the object-contact area due physically to the impact.

Abstract: A variable-color region (106) of a sports-playing structure of an information-presentation structure extends to an exposed surface (102) at a surface zone (112), normally appears along it as a principal color, and includes impact-sensitive and color-change components (182 and 184). A boundary line (1306/1308 or 1386/1388) extends along an in-bounds area (1302 or 1382) of the surface. A segment (192) of the impact-sensitive component responds to an object (104) impacting the zone at an object-contact area (116) by providing an impact effect if the impact meets threshold impact criteria. A segment (194) of the color-change component responds to the impact effect by causing an impact-dependent portion (138) of the region to temporarily appear along a print area (118) of the zone as changed color materially different from the principal color. The zone typically adjoins the boundary line or an internal line (1334 or 1396).

Abstract: A variable-color region (106) of a football-playing or baseball/softball-playing structure of an information-presentation structure extends to an exposed surface (102) at a surface zone (112) and normally appears along it as a principal color. An impact-dependent portion (138) of the variable-color region responds to an object (104) impacting the zone at an object-contact area (116) by temporarily appearing along a closely matching print area (118) of the zone as changed color materially different from the principal color. For football, the zone typically adjoins an end or side line (1446 or 1448) to help determine whether the object, typically a person's shoe, impacted the surface “in” or “out”. For baseball/softball, the zone typically adjoins a foul line (1506) to help determine whether the object, a baseball/softball, impacted the surface “fair” or “foul”.